SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abd600915f869bf93fa6cd13b70a693d9ae9a629241a5b23a737df1583382a2a' 
  AND token = 'p0v7gkYNAhzI1mSqFxpWgbSLy082L6mA52Kz3Xm8Ubs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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