SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92738a50b8469ea74ce8a66cc5aa1c91a7002d82488208ae2a533445b64dc54d' 
  AND token = 'bKcHUts4WVWdq4OdzDUA+uBLJANNxy97mwmACDIfr5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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