SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6bf083fb8fcf01e2cf150997f9442a511904a68db1f8fd62a368024cba37b67' 
  AND token = 'DhhfGz3Niq+s6GQJdMb6jwUD4O3a18yHKBVb6RauHQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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