SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0d373c9eaef6402106f64a33d42eaba8c26c0c69ea230727bfb6dc239356cc3' 
  AND token = 'u1DDNXYglJIW1Tjd9wM9mUgoVFPrtiXpfHx8794KCZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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