SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cec1117ebb3be076520eb2552e9760bbee36b812620092dee3b83de58ae5f97e' 
  AND token = 'snYEFUZLtxSupfDlYaDhNXouD0BhzgMuChmhMig635E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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