SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0c7d048623146c9dc358831977e1d4bc387cf10144c04353d00394f6e4b0aa' 
  AND token = 'f9eMHpWtoUJgBUBaacZg335zuUynN0GSbqeAhFiZrS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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