SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '223934e7e8b9dd9c24cfd6395eca390d2af296b8edb5a1e622cb2a056b7804ab' 
  AND token = 'OTYajQFvFMU/KRZOgmJSigoqXT2JldDxhitZ0KlNk9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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