SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0f906f6c0ae5f158bee4188069e4b85c3574f06901c2c50b8bc2404280a7993' 
  AND token = 'blM2b43xPVqjBBvf35lIkrJn/WgeARYbTBZIHXFktRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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