SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d7c313344eea84e3abc9221afa96e6ce040a89d5f97afbce5d8bfa78d1d0c57' 
  AND token = 'GvCZSgjvgSRyhXb+7NkXLhtvzpeBN5/RIpBFWUd9Qr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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