SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fad3528217e6805fac8f048db3574c9216e3454b137ded7226a61f9b27f278a1' 
  AND token = '4ljPS9rHOjOZACncgZ32flQLm9FniADcTY3Zw+nXaIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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