SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '454ef5cd212f6361d1d1d1462319016dbb1734c6a02f25e273c23930ebe71464' 
  AND token = 'gGq8HnlI6QlfwRJChS3DJdZZXrn7V+1dp54I/xrettI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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