SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3bc4273849807ab94fd7d3c60c202d421aa992f28c37f908fb5c1704577410f' 
  AND token = 'eqPKKCTAZBZPmFiPG+DMQfmjVs493l+se3wm6OOHgpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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