SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee84dd82ff505349b7298c85849555c0df8cc820800653e9dc79f1100167dfd8' 
  AND token = 'At2v8JiptHF3glXgkchfW7LHRROn7Eo89myXqsnpcQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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