SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf1001c2f0619749b40d1f221b1612b95c5734d1581b94ec570c27787cdb23f9' 
  AND token = 'TuwqiBRj9hjgbuGV16qHb4zsxsnLV4jtnO/CuOhLhEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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