SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6800fdafc49e0a76156d1fe6a625f1432d42151919c69dda58e09562719611e6' 
  AND token = 'y2oRx7AA2huFy2kMI8QP6VpbfVm5zt3UbzAS0al3ILg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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