SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd181673a9146dd6be520642bf6e5fbbc3dfa07a6b007ec2234e6b4214a3ff51' 
  AND token = 'xcIMNFPfJ74WExhbu/0zORpr5E7BsHaoaEL8UZxcdpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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