SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5265d141d98b70eaf400fef55698d73ff7c203b2d3f54ca211d91fc7384c54e9' 
  AND token = 'J3ZPFCQpWPgSOImsZCgWZL+AngDxh+KAMZN1xB0s9kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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