SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da739ecc33dd90db5153274ce92802ef94265c9df80ef8740b4d374baacd1db' 
  AND token = 'ydAjX5fvkLsEcwz5OeaBrTzclrg974ktNtMr5oc1mXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}