SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193cd3bfc9924a2403407f077355078a91db28d2ddd7da2b3d000fd0b19a999b' 
  AND token = 'LkI6whreHbqv36O7myobk85Ima7UI4RdcPg9Yx7UPI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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