SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b05857892054bf08cc504ddf26ca14ca5f96745f9bb24a8d0cc3c485b345d015' 
  AND token = 'zb0/oPZ9tV/4YJlL2ZmNwhxALVgXyDD2UDTBhtA7bhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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