SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2a8f9df914b69e40dacb3402b20400506aec17c9cda40b7900f851caf8f4675' 
  AND token = 'xSHEaVBmNWwCR5/4E6ig2tuY7bt8HSaNYgvipsZeBWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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