SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d483c2cc1276fd74bdff6ec9be9f35b393a41fd4e43b022d41f7478a4a12885' 
  AND token = '8+CK6ltqfymPB/GnvcGdC7VowjXVcicISKtryV07D/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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