SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aab61061533d10c335a978d88899b6af3fc19f9172972f144f3753763d34982c' 
  AND token = 'vc/pDpfMLUT+eyxnsOwAWoFeLh4bfOz0bs6r1TwLD48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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