SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65c6e89ca6a8f9c35e70048a58b37c336445656b755ce98e698c035fc7618a74' 
  AND token = '+FeK/iKGhqGPFUXMw2+KbucFBvz2lHZttw6gO09EhSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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