SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57c6113c3cd4a6544c49fd9f822cce5ed6bf5f3155f78bddbd24e93ce3a7a151' 
  AND token = '9S1W1fOEwQAoBJ3JwE9xRKIZnZ/DyPYRoS5jzLixQ/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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