SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b27c2b9a02305f7c6826bc5931ec4d9835db70734ec5881be3fc06071d87c77' 
  AND token = 'GjgnsUwMDyCgUF+6Jg8kHXVoyqYZmDsk2GurPmmByEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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