SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ebef77de8976abfe585b1abc17e19e8ae2151ae2a58bf04dcac38b08644e656' 
  AND token = 'octTlEo2bbRbLrnrAABiTbhiWsbFbhPmSJKcYzuq3mM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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