SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67db242ee30a94c7ba8cd447c38b8b2eaa2cd8506ac99d7c931bcd1bf6f6aa57' 
  AND token = 'FVbZYEzBjfMY9HxLWYeH/gdA96d5yw0RG60qKN7iFSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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