SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a75609a4c38b7720a3c0b049ea1b1b596650df6f44379527be88cac479adfd9' 
  AND token = 'kouALCKXvvULpnSZ9qnh6GjB/ojMY0x72mgy4EGr/+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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