SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43ca5e960199be47db7f906d5f2ec20f2b2139ecafb96efb197298200d6d037f' 
  AND token = 'OxVwAMFQlbVCwKSBpUsrVqQpuyjb6tC4J+TTCvj+33w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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