SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4204f7fb17c6081bee2e38275d65946e439a7bb31513874a08d735414ec9fb53' 
  AND token = 'gV8GnkgZXQLhrrUw/y8RIs5/TJayRTHMYK+1PmzVGPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}