SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7be3b0558aecacb6c73b17e19aa15561aca22520945f36f7691a8ccef5145a5' 
  AND token = 'ndFQkQtVJjZ9v60yviQ14n2Sv3eKks7kzmfymlsDQVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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