SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6128b97bb76138e9dd1a5bae647fef43e866626211c460a99a5e0733fdfe7b0' 
  AND token = 'SeLg4nQbeKKVhxYmUrXNRQKC0hvGAimV5RkZamDgijs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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