SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f3c4a097db12d27247aabbe260241a0537246909c43cf1362ccb2d1fdd0e774' 
  AND token = '2pLwxwLQDedfXw0zVU2Ghm2BmMIX97I9cEDzQFAK9Ik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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