SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e872a64decd05c579b8124de3cb9f35201ecc3194eae55c3b885b0a579a5be20' 
  AND token = '4lSlwEWYH03FVv4qJjrPUnplrd6TpoYgLaeFjVvYETY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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