SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e74b967c90abf7d063b85671060ae43a572e0607a1ad951fd24f5df28dbaed4' 
  AND token = 'uNxOYajbxn8H4Mjw7S6xx4yO93Gh1/2Z42STVVc5t4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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