SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34b40fd2ce900fb0d0d3f6a9ed90dfb16ec0b4ff82ba98a7f235eb842e5a501a' 
  AND token = 'DpBlPg/ggtSirjSqkgSKh0WOQH5F7rGTWSa23mpPQ30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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