SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40ad5a7eed20289f3631c183afb97737e29170d313b57ebae3560014e1c8322f' 
  AND token = 'vbVdzWnYJ+TZDOXoLo5ussfgKofdN1Tjew0lO9aw7ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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