SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea984d3d532134b07ad6df776a973f96afb62f3f529b1f7e571a93f47c44585' 
  AND token = 'tI/9vu7GuGjJZxGMN5gcnsCOU4N18YxybK8WKfAm3DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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