SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed196f930b323d279db0029e2ff68cb9a9cdf043243f21a35f3926f403928b08' 
  AND token = 'fF27aCH35Y2peVBys9bpNZeVdaOvIOLFQiplL02td0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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