SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc6439d62509e59fc10eb318e3fe2dbeea5d75734ebfb7b8ebc22db8f95e61b3' 
  AND token = '/hLziAYz4pRQ6MJlqWnJ+9akDK5IpwR/d/oyhPzPRG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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