SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2da4b529effc60997a39f10f8f8c13197195bf91eedc4cf6f2652b85932d6712' 
  AND token = 'MwaFQMCMHHbWPzgRXMKAKhYSUtRJYMO51i/zNGKcNsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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