SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a12dfeb59e57f8be3994545c8f4be1b2bd811eec18dd5e77e1e2f8df8622e8' 
  AND token = 'txFhG9n5zkl9nOzNi3DdQoeMYyS4jDgnrAeY1ePQVZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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