SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '687f08b10dfe41633937428176d424285aa5b3d1bba5f9c0c94b45f354792bee' 
  AND token = 'HCYU1lidf+1lnLgX/F3OeiyFpFnJxF1iPye++Z+9rmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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