SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa8c952bacc4d44f5a0f5de70da69ec851809da849524f32627247abe86fea68' 
  AND token = 'yKS5qftTaWNswx/XlINSmdHhtjOtv8jCHcGwRt2GkyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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