SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f4d35cff7c52d53b12eddb0d0334480e8ab9b6206e07c0a53b052eb23b1ecb29' 
  AND token = 'fidxs67ZDv9zjgHeofpoo+qH+8Rn7hxPmWts3Mi2PG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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