SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5914c8f5625d786eb1b05b83d099c67a28f09ab76f51cba934a9ac936385ed5' 
  AND token = 'Xv+yW5POeAHVNzuFVCgBKoP9bzyNmGy2urLerh+wuDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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