SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069f92da86acca95466c107434ed0335a3a0d4b960f564916d396731699ecd9b' 
  AND token = 'oUenCVO0KExF3YqCYLz+Suwof+52GDsEvC0gv1o65IE=' 
  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"
    }
  }
}