SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae04a3d9b1cbf40540d85485a75bc891f22ce1f1042bdfab586b89820b93512e' 
  AND token = 'vGrkq8HnyjSdnUN3PU9WZC0zZTQCyU/5qvOgbbbEiXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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