SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cbb9cc42ad18deda543758142f7fbcecfadc533db688db54eca6b8d05236695' 
  AND token = 'yu3FkFrzgkthHlQNHf8Cc/g3qcW9x8S6mqYCHlq3hqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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