SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae16e5bdb291e72b6da07ec6f9b74876bbb787c73e6982c85ce0ddae49eb7cf' 
  AND token = 'B6GwsKoHwBd39uPEXDT5OCwQbwEZ9piiHiY/N6VbYGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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