SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e43562b691da47c9fc2bd5e70438f3d826fa6717ee3c59a7db2b61cd11b75397' 
  AND token = 'rxPUleE0mpI+T1HZKAquhgzoePT9nYYyGJOExwRhvwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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