SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a437249dc1a39062297d42727bd938672458ad20582fbebaf7eefce6383153d' 
  AND token = 'upL7SO68XLIXrl6egnkMQGyQAizxQj6iveXbkmbI+m0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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