SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b59639f1fa7490d4a5dc2b1589a82172dff6eb475f0b9d32c6ca45a7e4d0bdc' 
  AND token = '+9aL/bnEMUULcHYWyTsqGJe+pq7awOXFtzGmgxsHJnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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