SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '972f6f9a18219872e109ee3b351eaad221486cab6f0e33fe7c7a9e5de3bb5e3f' 
  AND token = 'tpQRYV4yDqlC2EkXzo84Ob1i6zDKTLgMn9tJiHD6TMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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