Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec5875013e0a114a2974eba18a8eab8f57844950de59567c46e91ad41d805844' 
  AND token = 'aE1FHN2I5bMEL/Uwk4/PMZ4Md6RqxbZttnzrdi2NVGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}