SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c9e014dedbd9e8c2a14e5f32419727827f109e800f3ffe5949e1e3a780dce4e' 
  AND token = 'Jnk1vTf3LQjg8R9uMwaxG808HbFevBDC4cbE6cT304g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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