SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f479e0968ddb18666095d85848bc703c95fea2767b76516ea7fb87ead43b53c6' 
  AND token = 'Ik3YW27KJ0GNpq6wDRnEtpfdOkfHei12XeVG+QdoEOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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