SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '035d4a99ee06f5fd2338eb02e31352c11c60dd957843b474eca53bd995451524' 
  AND token = 'ZaWmpyCNn+mztjUCdWtIxC052Shn1koW6Ul8yak1Xrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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