SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af530fb5a52288fe3ece794bd5ec61749d20ace2468d7a23c72389e3f7deded3' 
  AND token = 'lMog5XAelN6jrZT+PQ2exvMA8FG4btql2XO3O4itGQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}