SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e270ab957ef3d5199fc7382325a5124e65affa649270d58931286cb903b7017' 
  AND token = 'wzkNPNlk0ilnmQhx+ASBwEMhKYSyASRjLwY0ogisgCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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