SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1f00d41404604e3f5712a0e3174d9bcab275e13b34dadcdcbc376bf31e35d5b' 
  AND token = 'E0hV4SMQeCz6dAVuKzsL4M3+0oX2cwu8IKY2BJjI1Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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