SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba3f449544c292220c6513fab60f69903d126a2cc6c8419d4d9ac9c2f2681ba' 
  AND token = 'Wevv78wgSj14DtMLJ2PZDM/d+OpiyQuf3v0jVhG/7oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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