SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29110510a016dd4a19c486cc078b788fa8005b512290d7dc60c69fa2c55d2c18' 
  AND token = 'y1mmIJj8SrhFn7Qk5Zpl82a1PGoZrzMXomalXEWOYxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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