SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7371dbeabc632ebc161ba76fc7a9c73964d8ee104f8cb65d625fa2c2702c415' 
  AND token = 'Az1JVa7udBtKWkQvBDYhsUm18C3uJw/SOXO0AcQZH5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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