SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4743c832a3506e5b69d1b46539a464e8e67016b522f4afa145a21ab24beebd36' 
  AND token = 'Dg5Pow5mvpkCfE27MkGd7XkjPqg6bC49U/4eK1m3Lek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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