SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '33b8ade6f77823d9221a59d4be650c888fba6d1e26d243101c04577de0318081' 
  AND token = 'mhOAEKhtzDHmZit9Zp6VEPXHqToEoLPDPOrIVpkuPgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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