SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4e891285ab7157284a43c83c249ee7a76fba5f4d1731fb3822f101921b5f8bf' 
  AND token = 'UfOb+l4ShCnZl5YXEAvY/XCZpPXJpSGV+P/T4YZfBvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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