SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a37eae6a0988818f74f8515bc8e1b0e474ea297e1549424d7b91a582596f11d4' 
  AND token = 'e03pPiiisrcM7SxvvLbMViYxQuyuu3zHqqjlmY/fFW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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