SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9289ed5ca2f66f43ffa447599f50c885264fa1aae8818f445c7a878931ac3ac3' 
  AND token = 'v7KF8hAi3lEBXgTxEqDwPsgemsMWKu9v3br/wUZq1w8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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