SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45891962c76e71406032aafa58970838d679853e4b9097e441724d44435ebce9' 
  AND token = 'ibOIhelWhuFdUVc8rsqr/7MFpSldht4s6w1csPRS/xI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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